The simplest alarm scheme for a home. Homemade car alarm. Do-it-yourself home alarm system - installation work

There are many industrial security alarms that you can buy or simply contact a company that installs security alarms in your home or country house. An article for those who don't like to spend money. Homemade security alarm schemes there are also a lot but, basically, they require professional radio engineering knowledge and skills. Here we describe the principle and schemes of the simplest, yet reliable methods and standalone devices protection against penetration.
The principle itself - upon penetration, a sound and (or) light alarm is activated - an old, proven method that deters thieves in 98%. By the way, not even the coolest alarm system, or even connecting to a security company’s remote control, will protect you 100%. It’s like a car - if it’s ordered, nothing can save it.

But let's not be so pessimistic. Such cases are very rare, especially if you are not an oil tycoon or the like, and you don’t have half your house (dacha) with diamonds, then you definitely won’t fall under the “order”. But ordinary thieves, who commit 99.9% of thefts, will never steal if the light (sound) alarm goes off. It is much easier and safer for them to find and clean out another object that is not equipped with anything - fortunately there are plenty of them and they have a huge choice. From these considerations it follows that it is not at all necessary to spend a lot of money on the purchase and installation of a security alarm, but by making and installing even the simplest, homemade one, you increase the safety of your acquired property, your nerves and your health by many orders of magnitude. The choice, of course, is yours - learn from the mistakes of others; when trouble comes to you, it will be too late.

For the simplest alarm It is enough to install intrusion sensors on doors and windows (a regular reed switch and a magnet cost pennies) and connect them to the alarm circuit. The sensor is installed: a magnet on the moving part of the door or window, a reed switch on the non-moving part, so that the reed switch is closed when closed.

All reed switches are connected in series. The alarm will be triggered when the circuit breaks anywhere. Below is general scheme such a device.

Here:
I - detector (chain security sensors),
Op. - siren (sound, light or combined)
P - control relay
VT - transistor (or thyristor)
R - resistor
S - switch for arming/disarming,
Cupr. - relay contacts that control the notification
Kbl. - self-locking contacts
+U - power supply

When the detector is triggered, the warning device is activated. The notification can be light, sound, or combined. In addition, with a little modification, the alarm signal can be transmitted to the remote control, mobile phone etc.

A transistor is used to invert the sensor signal and does so as follows. While the detector contacts are closed, they close the base of the transistor to the common wire, the base current is zero, and the collector current, respectively, is also zero. When the alarm sensor contacts open through resistor R, the base current opens a transistor that turns on the relay.

You can use a diagram that shows how you can bring the described inverter to banal contacts and eliminate radio elements altogether.

When voltage is applied to the relay through the triggered (closed) contact of the alarm sensor, it is activated, turning on the control. the right system(alerts, data transfers). At the same time, another group of contacts blocks the sensor contacts and, regardless of its further state, keeps the relay in the activated state. You can now turn off the alarm by opening switch S. By closing this switch again, we will turn the alarm system back into standby mode. As you can see, everything is more than simple. However, such a circuit consumes slightly more energy, since the relay coil will be energized in security mode.

A significant drawback of this scheme is that when triggered, it can only be turned off manually. Therefore, such a scheme can be used in the immediate vicinity of a protected object, for example, a nearby garage, barn, etc.

Security alarm circuit with time relay

The basis for constructing the following security alarm circuits a time relay K2 of type RVP72-3-221-ОOU4 or similar is taken, which has two groups of contacts, one of which - K2.1 - operates instantly, and the second - K2.2 - with an adjustable delay ranging from 1 to 180 seconds. The delay is set for 5-10 seconds so that when entering the premises the owner has time to turn off the alarm using the S3 button (installed in a hidden place) before the sound or light signal is activated. Complete disconnection of the alarm system from the network is carried out by switch S1 (toggle switch or any other for 220 V). The door position signal sensor is the S4 button (type KM2-1 or similar small-sized) installed on the door frame. Button S2 is installed in front of the door to the protected premises and it allows you to turn the alarm circuit into ARM mode after exiting. Relay K1 can be used of any type with an operating voltage of 220 V. For safety reasons, it is recommended to use a 12V or 24V relay.

In SECURITY mode, this circuit does not consume electricity, but when the alarm is triggered, the siren (or bell) will sound until the alarm is turned off by button S3 or toggle switch S1 inside the apartment. The same drawback as in the previous scheme.

To eliminate this drawback, the circuit must be supplemented with another short-circuit time relay, illogical to K2 (shown with a dotted line in the diagram). The response time of the KZ.1 contacts is set to a delay of 120-180 seconds. After this time, the alarm circuit will turn off the siren and will remain in this state until the ARM mode is turned on.

In the same way, you can make a simple car alarm yourself.

And another homemade alarm circuit uses only one time relay.

The sounding time of the siren (and/or light) is set in the relay. The circuit will go into standby ARM mode after a short-term de-energization of the circuit, after activation, or upon initial switching on.

S1 - toggle switch to turn on/off the security alarm;
S2 - toggle switch is used to temporarily disable the bell (or siren) while monitoring the operation of the security device

The circuit uses thyristor VS1, which ensures fire and electrical safety. There will be no life-threatening voltage on the security sensor circuit. This scheme allows you to connect many sensors in series to the security circuit. Sensors can be installed on window glass in the form of a strip of metal foil glued around the perimeter. They are triggered when the glass breaks. Naturally, any reed switches will do, in any quantity. All are connected in series into a common signal network. Before arming, check whether the windows are closed, All sensors except front door must be in the closed position.

You can use a similar other thyristor. In this case, you may need to select resistor R1. Resistor type - PEV-10 or similar with a permissible power of 7...10 W. It is also possible to use several series-connected resistors of a lower value.

When the security sensor circuit breaks, relay K2 is triggered (the same as in the previous diagram) and its contacts K2.1 contact the self-blocking unit. Relay K1 is also activated, which will turn off after a specified time (120-180 sec.) by contacts K2.2.

Relay K1 allows you to connect a powerful output load. You can use any siren as a sound source, for example SS-1 or any powerful bell at your discretion.

The HL2 indicator light and the S2 toggle switch are auxiliary and their use is optional and does not affect the operation of the circuit.

These are the simplest homemade security alarm schemes for a home, cottage or garage that anyone can assemble with their own hands.
Good luck in ensuring the safety of your property.

If you are the owner of an expensive car, then most of all this article is not for you. And if you have a rather modest car and you want to protect your car at minimal cost (which is not at all proportional to the quality), then this description is for you.
The point is that car alarm should not cost more than 5% of its market value, which for a used car is an amount for which you cannot buy a ready-made, more or less reliable alarm system. The danger for a car without an alarm system is not only in its theft, but also in the entry into the interior, theft of property, documents, etc., which is very common in current conditions.
The damage may be minor or may exceed the value of the vehicle itself. In the traffic police, such cases are often not considered at all, since there is little evidence for them and the case is not opened at all, stating that you yourself forgot your purse or documents somewhere, and you had no money at all. My friends had several similar cases, although the cars were equipped with commercial alarms.
But the fact is that scammers and thieves have long learned to bypass standard alarm systems that are not expensive (although this is for some), and quite expensive. And it has become much easier to open (steal or rob) a car equipped with such a standard purchased alarm system. Now there are many different scanners with which an attacker reads the code of your alarm when you arm your car by sending a command via radio from the key fob.

That’s it, the “bad person” already has your code and can easily both open and close the car without attracting attention at all. Further, I think everything is clear to everyone. Therefore, having such an alarm system, you significantly increase the potential theft or theft from the car, even compared to if you simply locked it with a key, without the possibility of remotely opening the doors. And if you also take into account the human factor - the technician who installs the alarm system for you can naturally know how to turn it off, make a duplicate, etc.
Of course, most masters are decent people, but the facts show that if there is an opportunity, someone will always take advantage of it. The data can be transferred to interested parties and “shot” a year or two after the alarm is installed. It will be almost impossible to connect this into one whole, and even more so to prove it.
There are still many arguments not in favor of standard purchased car alarms of the low and middle class, not to mention the costly part.

Let's look at the functions that a simple, inexpensive, DIY car alarm should perform:

• The alarm should respond to intrusion into the car, for example, using an IR motion sensor, or from standard light buttons that are activated when a door or trunk is opened (the cheapest option, easy to implement, but nevertheless quite functional).
• A car alarm should notify you of intrusion using sound, a standard signal or an additional siren. This alert should last for a certain amount of time, such as two to five minutes, and then automatically turn off.
• After the alarm is triggered, the system should go into unauthorized entry mode - trigger repeatedly, block the engine from starting, etc.
• - The car alarm must consume low current, excluding the discharge of the battery (standard or additional) during long-term parking of the car under guard.
• Switching mechanism, switching to security mode and disabling the alarm. In a simple case, a short delay (5-10s) after turning on the secret toggle switch, while leaving the car and closing the door.
• Easy to manufacture and connect with low financial costs and maximum efficiency.

Such an alarm will reliably protect even such a product as the Six-wheeled "Cossack Hummer"

Below is one of the most simple car alarm circuits that you can make yourself.

The car alarm combines an acoustic alarm that is triggered by the closure of sensors (door and trunk light buttons) and when the ignition is turned on and blocks the engine from starting.
This circuit is suitable for installation on domestic cars equipped with a classic contact ignition system (VAZ, Moskvich, Volga, etc.) and any foreign cars with a similar contact ignition system. (Previously, all cars had a contact ignition system - turn the key - the contacts closed). Installation in many new cars is also possible.

Homemade car alarm circuit is quite simple and understandable to any novice radio amateur. All details are publicly available and cost pennies. Connection to electrical diagram car is also shown in the diagram. The bold line highlights the alarm unit itself, which is assembled in a small plastic case, selected from those available or can be purchased on the radio market - to suit your taste.

Everything outside the bold rectangle is the electrical equipment elements of your car, as well as other additional elements that are introduced into the car circuit (Sensors K2 and KZ, two relays P1 and P2, toggle switch 51).

Two types of contact sensors are used - standard interior lighting switches located in the car doors (they are connected in parallel, so the diagram shows one K1 sensor and one H1 lighting lamp), and specially installed sensors (such as door sensors) under the hood and trunk lid, if the trunk It is not equipped with a standard switch, similar to a door switch - so that when closed, their buttons are pressed and the contacts are open. When opened, the contacts must close.

The standard signal of your favorite car or an installed purchased siren can be used as a source of sound signal for the car alarm system. The signal is turned on using an additional electromagnetic relay of sufficient power (since a fair amount of current passes through the signal coil), which must be installed in the engine compartment of the car - P1. The same relay P2 is used to block the ignition system. In principle, this relay can be placed in the alarm box itself. Its winding is connected in parallel with winding P1 and when the alarm is triggered, relay P2 with its contacts bypasses capacitor C of the ignition system, which makes it impossible to spark and start the engine.

The car alarm is turned on using microswitch 51, which must be installed in a “secret place” inside the car (usually somewhere under the panel), known only to you and trusted persons. After turning on the power, the device will not respond to the status of all sensors for 15-20 seconds. This time is allotted for getting out of the car and closing the doors. After this time, the car alarm goes into security mode.

To increase reliability, you can use an independent additional small battery, depending on your desire, desire and financial capabilities.

Even without an independent power source, such an alarm system modern conditions It will be more reliable than a simple store-bought one with a remote control. It’s clear about the cost.

The system is economical. In standby mode it consumes less than 0.7 mA, the trigger mode is 1.1 mA, and the signal or siren current is 0.2-0.5 A

Additionally, you can add an infrared motion sensor - purchased or if you have one lying around the household.

If the sensor is rated at 220V, it needs to be converted to 12V (8-20 Volts). A standard household motion sensor needs to be opened. The spherical part is removed by bending one support. The halves are secured with latches.
Take out the board. A sensor is a passive IR receiver that responds to changes in IR radiation hitting it. Typically, the viewing angle of the motion sensor is 180 degrees.

One more simple circuit car alarm without chips

The circuit works on a similar principle, using the same sensors as in the previous case

Brief description:

SA2-SAn - intrusion sensors (door buttons, etc.). Diodes VD5-VDn are used to decouple the sensors, if they are used for other purposes. If the sensors are only for signaling, diodes can be excluded.

The supply voltage supplied from any closed sensor is supplied to VD1 through R1 C1. Circuit R1 C1 creates a short pulse of current even if the sensor remains closed. Capacitor C2 prevents the alarm from going off when toggle switch SA1 is turned off.

The output switch and multivibrator are assembled on elements C4, R4, R5, VT2, K1. The duration of K1 being in the on position is determined by the selection of resistor R5 (you can install a variable resistor), and in the off position - R4. The overall pulse frequency is set by C4. This part of the circuit requires more careful configuration. Approximately around 2 Hz.

An assembly is assembled on elements C3, VD3, VD4, which forms a delay in the alarm when the intrusion sensor is closed. This is necessary to delay the activation of the siren when the owner opens the car for 4-8 seconds to turn off the device (so as not to scare others :-)). The delay duration is set by capacitor C3. The discharge of the capacitor when the power is turned off is provided by resistor R3.

In this scheme there is no node that would turn off the alarm after some time; this is the simplest option. If desired, such a unit can be modified, slightly complicating the design, or you can use an autonomous time relay with periodic reset.

VD1 - any low-power thyristor, for example KU101. You just need to select C1 (increase if the alarm does not trigger when the sensor is closed), R2 (decrease if it does not trigger) and C2 (increase if it triggers immediately when the circuit power is turned on). Diodes - any low-power ones. Relay K1 - RES55A, or similar (selected according to the power of the switched current of the siren signal). If you use a more powerful relay (more than 1A), then you will need to significantly increase the capacitance of capacitors C3 and C4 (this will entail an increase in the size of the device). Therefore, if you have a fairly powerful load, it is better to connect a powerful relay to the RES55A output. Transistors can also be any, with the appropriate transition structure, and VT2 must withstand the relay switching current. SA1 - any small-sized switch (toggle switch).

To arm the car alarm:
1. Turn on toggle switch SA1 with the sensor closed (with open door). The circuit will not turn on in this position and can remain indefinitely.
2. Close the door - the circuit goes into security mode.

To turn off the car alarm:
1. Open the door (this will close the intrusion sensor).
2. Quickly, within 8-10 seconds. disarm - turn off toggle switch SA1.

Today you will learn how to make a homemade gsm alarm from cell phone. Such a security system can guard your dacha, garage or car.

This article has been planned for a long time, it is a “mobile GSM add-on” to . After reading the article to the end, you will learn how to make a cellular alarm out of any existing alarm system, but more on that a little later..

This add-on implements the notification function on a cell phone and allows the owner to control the situation about the “integrity” of the protected object anywhere in the world using mobile communications. Such an alarm system is the cheapest option and requires only an investment in an old cell phone, a battery + some parts, solder and free time.

Materials and tools required for the manufacture of GSM alarms:

• cell phone Nokia phone 1100 (or any other mobile phone with a shortcut function that !Attention! implemented by pressing the button once and holding it in this position).
• headset (headphone with microphone) used for audio monitoring of the room
• soldering iron
• solder
• wire
• reed switch (or push-button door open sensor)
• 12 Volt acid-gel battery (the larger the capacity, the longer the “autonomy” in case of a 220V network outage)
• battery charger

The principle of operation of a homemade mobile alarm system based on a cellular phone

Ways to connect a cell phone to an alarm system:

The methods described above to establish interaction between a security alarm and a cell phone are valid for any alarm system. Thus, you can “attach” a GSM alert to any existing alarm system (for example, to a standard car alarm). Only one thing is required from it: close the relay contacts, or supply 12 Volts during “triggering” (for example, you can take 12 Volts from the terminals of a car siren, only then you will need to set up the “quiet mode” so that when arming or disarming the alarm the alarm will not “ quack" based on what option you have, choose the appropriate scheme.

How to organize uninterrupted power supply for GSM alarm systems.

We have figured out how the alarm system interacts with a mobile phone, there is one more issue left to solve - to ensure the phone is powered uninterruptedly 24*7. There are several options available:

In the future, I plan to write a number of articles on the topic of security systems: how to make a security system from a video recorder with internet alert and an article about the types of sensors for which will help make the protection of your apartments, garages, and cottages more complete and reliable.

I wish you success in creating an alarm system, as well as the safety of your property!

This article provides diagrams of the simplest electronic alarms, which can be made by anyone who is at least minimally familiar with electronics or simply knows how to hold a soldering iron in their hand. Such alarms are useful in many cases. They can be placed on the windows if the house has small child, which can open them. There is a guarded parking lot on the doors of the apartment or garage. And when triggered, the watchman will call the police. You can install such an alarm in your apartment if you are friends with your neighbors. Even if you are going on a hike, it is not a sin to spread a security line around the camp at night in case wild animals or strangers appear.

First scheme Electronic signaling is simple to the extreme, it couldn’t be simpler. This is just one transistor, resistor and executive relay. If an audible alarm is expected, then instead of a relay, an audible siren or bell is turned on.

Working principle: The security loop is a thin wire, or a closed contact. When the wire is intact (or the contact is closed), the base of the transistor is grounded and the transistor is turned off. No current flows between the collector and emitter.

If the security wire is broken or the contact is opened, the base will be connected to the power source through resistor R1, the transistor will open and the relay (or siren) will operate. You can turn it off only by turning off the power or restoring the security loop.
Such an alarm can be used to protect your belongings, for example. A reed switch is used as a security contact; the alarm is hidden in the side pocket of a bag or backpack, and a magnet is placed nearby. If the magnet is removed from the alarm itself (move the thing), the siren will squeal loudly.

Second scheme with more advanced user features

As in the first case, a security loop, a normally closed (in security mode) contact or a reed switch closed by a magnetic field serves as a sensor. If the loop is broken, an alarm is triggered and continues to operate until the power is turned off. Restoring the loop does not turn off the alarm; it will still continue to work for some time. The alarm has a temporary blocking button, which is necessary for the owner to leave the protected area. The alarm also has a response delay, which is necessary for the owner to turn it off when he enters the protected area.

Let's analyze the operation of the circuit. Before arming the alarm, you must turn off (open) switch S1. It must be installed in a secret place near the entrance. You can use, for example, a hidden reed switch, which is closed or opened by moving an object with a magnet built into it, etc. This switch blocks the operation of the system and it stops responding to a broken loop. When leaving, switch S1 opens and capacitor C2 begins to charge through resistor R2. Until the capacitor is charged to a certain value, the system is “blind”. And you have time to leave the facility by restoring the security loop or closing the contacts. By selecting the values ​​of resistor R2 and capacitor C2, achieve an acceptable output delay for yourself.

If the security loop is broken, then capacitor C1 will begin to charge through resistor R1. This pair creates a slight delay in the alarm, and the owner has time to neutralize it by turning on switch S1. It is necessary to select the values ​​of the resistor and capacitor for a comfortable response delay time.
If the loop is broken by an intruder who does not know how to turn off the alarm, then some time after the loop is broken, the alarm will go off (both inputs of element D1.1 will be logical “1”, respectively, the output will be “0”. Having passed through the inverter D1 .2 it will become “1” again and open transistor VT1. The transistor will discharge capacitor C3 and open transistor VT2 through the inverter, which will force the executive relay to operate or turn on the siren.

Even if the attacker quickly restores the loop, the siren will continue to work, since capacitor C3 will be charged for sufficient time through resistor R3. It is the ratings of this pair that determine the operating time of the alarm after the loop is restored. If the loop is not restored, the alarm will work continuously.
Microcircuit - K561LA7, transistors - any n-p-n (KT315, KT815, etc.) Power source - any with a voltage of +5 - +15 Volts. The executive relay or siren can be connected to a more powerful power source than the circuit itself. In standby mode, the circuit consumes virtually no current (at the level of battery self-discharge).

Alexey

A dacha or separate outbuildings in the courtyard of a private house can also become the target of attacks by thieves. Install an industrial security system impractical, it will cost more than all the things stored in such premises.

But you shouldn’t leave it completely without protection; those who like to make money at someone else’s expense, if they don’t take away your property, they will cause damage to the structure of the building, the restoration of which will require funds. Therefore, many believe that the ideal solution would be a simple security alarm, almost anyone can do it with their own hands.

What is included in such a system?

Typically, such models use an IR motion sensor, siren and other components to assemble the device. But since wired detectors are designed to operate from a 220 V network, it will have to be upgraded and converted to 12 V. To do this, a 6 V relay is added to the circuit. Power is supplied to the sensor through a switch. When the device is triggered, voltage is supplied to the relay winding, it is activated and causes the siren to turn on.

If necessary, up to several audio signal devices can be connected to such a circuit. The presence of a regulator in the sensor allows you to set the signal time after the siren is triggered; usually it is no more than 10 seconds. The circuit is turned off using a special device that is switched with a key.

The considered simple security alarm is one of the most primitive; it is easy to assemble with your own hands and is economical in terms of energy consumption. For example, for the winter you will need no more than 16 alkaline batteries. This scheme works in any conditions and can withstand even negative temperatures, so it is quite suitable for installation in an unheated country house.

Types of homemade circuits

Assembling and installing the system with your own hands has a number of advantages. It allows you to save money and eliminates the possibility of employees of the installation company helping thieves. But the most important thing is that during the manufacturing and installation process you will carefully study the structure of the alarm system, you will be able to troubleshoot problems yourself, make adjustments to it by connecting additional sensors and improve your design.

Let's watch the video, homemade system security:

There are several ways to equip your home with a simple security alarm, assembled and installed yourself. The first and simplest, but at the same time the most expensive, is to invite employees of a special company who will develop the project, select necessary equipment, install it and perform commissioning work. This option is suitable for residential and warehouse premises, but is unsuitable for a summer residence, since the costs will exceed the value of the property stored there.

Another way is to buy equipment, carefully study the instructions for its installation and operation, and perform the installation yourself. In general, there is nothing impossible in this approach.

Moreover, many trading companies are engaged in programming control panels, which will save you from the need to purchase a programmer, study the rules of working with it and try to complete this stage of work without outside help.

For the most simple option alarm system, you need to program the device loops, turn them on shared network and write into memory the required number of keys for access. They will be required to disarm and arm the object. In addition, the switching on of the light device is programmed, with the operating time limited to 10-20 minutes and a relay output for dialing to a mobile phone.

Let's watch the video, an addition to the main alarm using a mobile phone;

On the market you can find many GSM modules for sending a signal to a specified number when the contacts on one of the inputs are closed. These devices are universal and can be connected to any control panel.

If you already have, then the next step is to connect them to the programmed device, which is quite easy for anyone who is able to find the “plus” and “minus” in the circuit. Again, with self-installation, you will be able to understand in detail the routing of cables and, in the event of a breakdown, fix it without problems.

Watch a video about the purchased GSM system:

For those who are not satisfied with a wired system, you can choose the wireless option. In this case, installation is even simplified, since you only need to hang the sensors in the required places and insert batteries into them. The advantage of such systems is the ability to operate on one power source for up to a year, and their cost, when equipped with one or two sensors, is low.

Detectors also have their advantages. They can be transferred from one place to another, if necessary, without much hassle. The option discussed above can be made cheaper by purchasing used equipment. This option is easy to assemble with your own hands.

Another, cheapest, but also ineffective way is to install dummies. Such a system is unlikely to frighten a seasoned thief, but it can stop boys who decide to play pranks at someone else’s dacha.

Project for a homemade alarm system - is it necessary or not?

Having decided to install a security system in a house, the first thing you have to solve is the development and execution of documentation. A professionally completed project is the basis for the future system, if its installation will be carried out by employees of a special company. But what about those who decided to do all the work themselves?

If you are installing an alarm system in a public place, then the project must be required, otherwise the supervisory services will not accept the system. But a house is not one of these objects, so installing equipment in it will only require a sensor circuit, which is necessary for future maintenance.

The simplest circuits are based on a time relay

We will consider only two of them. The first security alarm for a home that you can assemble with your own hands is based on a time relay. It has two groups of contacts, one of which operates instantly, and the second after 5-10 seconds. This is necessary so that the owner of the facility, upon entering it, has time to turn off the system with a special button, which is installed in a hidden place.

Complete shutdown is performed using a special toggle switch. With this design, a position sensor is installed on the door frame. Before entering, a button is installed that turns the circuit into security mode after the owner leaves. Typically, such complexes use a 12 or 24 V relay.

Watch the video, addition to GSM alarm system, 12 V relay:

The disadvantage of the scheme is that the siren sounds until the alarm is turned off by the button. To eliminate it, the system is supplemented with another relay, the contact response time of which does not exceed 120-180 seconds. After this period, the siren turns off and remains in this position until the security mode is turned on.

The second one offered for self-assembly is based on a single relay. The operating time of the siren is set using a relay. And it goes into standby mode after the system is de-energized. This circuit uses a thyristor to ensure fire and electrical safety of the equipment.

It is designed to connect a large number of sensors for various purposes. For example, for glass, you can use detectors in the form of strips of metal foil that are triggered when they break. Their connection to the common network is performed sequentially.

It is possible to use other types of thyristors. For example, model PEV-10 with a power of up to 10 W or several with a lower rating.

If the circuit breaks, the relay will operate, which will turn on the siren or any powerful bell. Additionally, a light bulb may be included in the circuit, which is an auxiliary element that does not affect the operation of the system.

Is this method of protection reliable?

Property protection is becoming the most pressing issue in our time. And the way to solve it depends on many factors, but cost is often decisive among them.

It makes no sense to install an alarm system whose price exceeds the value of the protected property. For such cases, the ideal solution is to develop and install the system yourself.

But will such an alarm be effective? In some cases, it will certainly be able to scare away thieves, but for reliable protection it is better to use professional equipment and the services of specialists. The use of remote security will not only provide reliable security, but will also allow you to return funds if a robbery is committed.